Behaviour of As and Sb in ‘Technogenic Lake — Environment’ System

Abstract

In this presentation the geochemical state of the Komsomolsk collection pond (technogenic lake) is discussed. The pond has been formed as a result of stockpilling and settling of waste waters after cyanidation of gold-arsenopyrite-quartz ores and after antimony recovery (Kemerovo region, SouthWest Siberia). Tailings impoundment is located in a valley at an altitude of 800 m above sea level, closed from three sides by the natural relief and from the fourth one by the filled dump. It contains about 3.5 mln. tons of mineral processing waste. The main sulphide minerals are pyrite, pyrrhotite, and arsenopyrite. Together with galena, chalkopyrite and sphalerite sulphide minerals represent less than 5%. Gangue minerals are composed mainly by quartz, feldspar, calcite. In general neutralization of draining solutions was done by adding Fe(SO)4.7H20 to the settler, and the effluent was subsequently discharged into river Voskresenka. The objectives of this investigation were: a) to determine tendencies of behaviour of the potentially dangerous components: heavy metals As, and Sb in 'water solid tailings' system during storage period; b) to study geochemical conditions of the lake to reveal speciation of toxic components; c) to establish accumulation routes of dissolved forms of toxic substances in pore and underground waters, Field and analytical methods. Field work include sampling of different components: surface lake water; sediments; dry part of the tailings impoundment; underground water. Three profiles of surface water of the lake were sampled. The water was filtered through filters with a pore size of 0.45 gin. Three 30-60 cm deep sediment cores were taken and sliced. First core (1 1) was taken from the lake part located near the pulp-line to study a substance with minimal action of oxidizing process during storage United Inst. of Geol., Geoph., and Mineral., Koptug prospect 3, Novosibirsk 630090, Russia